New study sheds light on stillwater barbel

Although the barbel has evolved as a river fish, there has been a growing trend towards stocking them into stillwater fisheries.

Whilst this has split opinions among fishery interests, the Environment Agency’s view is that some stillwaters are suitable for the fish to thrive. Water quality is the key factor, but it is difficult to determine which waters are suitable. A new study has provided the EA with a better way of doing this.

The study was carried out by EA Fisheries Scientist Ms Ayesha Taylor for her Hull University MSc Fisheries Science Degree thesis on the growth of stocked barbel in stillwater fisheries.

She monitored the growth rates of barbel in 10 stillwater fisheries and 30 rivers, including the Thames, Great Ouse, Teme and Nidd. In order not to compromise the study the participating fisheries have remained anonymous.

“Barbel are a bottom-dwelling species preferring cleaner rivers with stretches of gravel, riffles, pools and deeper glides. Its torpedo-shaped body with large triangular pectoral fins is designed to cope with fast river flows,” explained Environment Agency Fisheries Policy Manager Adrian Taylor.

“But the study shows stillwaters which are not heavily stocked and which have few, if any, carp offer a suitable environment for barbel to feed, grow and maintain health and condition.

“Water quality determines whether barbel can thrive in stillwaters. However, this can vary even on a daily basis, and so it is difficult to be precise about which stillwaters are suitable on this basis. Water quality is heavily influenced by stock density, and the presence of carp in particular, so we can now use these criteria to determine suitability. In summary, the way a fishery is managed is key to whether or not barbel can be stocked.

“Our policy, therefore, remains the same: barbel may be stocked into suitable stillwaters. However, the guidance we use to determine suitability will be changed so it is based broadly on fishery type, rather than water quality.”

The Environment Agency’s new guidance is that barbel should not be stocked into stillwaters that have:-• an enhanced stock density;• a predominance of carp;• a history of mortalities.

From 2000 – 2006 326 applications to stock barbel in stillwaters were granted across 283 different sites. In 2005 there were 60 consented applications.

The existing rules for introducing barbel into stillwaters are:-

• Wild caught river fish should not be used to stock stillwaters. Such stocks should be obtained from a fish farm or existing stillwater population.

• The nature of the receiving waterbody must be suitable for the fish to thrive in terms of feeding, growth, health and condition. It is not necessary for the fish to be able to breed.

• The application should be supported by appropriate water quality information. (Note that this final requirement will be replaced with the new policy guidance based on fishery type.